Flair 58 rotating plunger valve assembly.

A haven dedicated to manual espresso machine aficionados.
MCal2003

#1: Post by MCal2003 »

Wasn't sure until Flair added an accessory to deal with the problem that I had a one off issue. The rotating valve. Not sure what actually causes the assembly to slowly, but steady rotate. One thing I have notice is it is in a counter-clockwise direction. Same direction as securing the portafilter. Coincidence? Cause and effect?

The ? Which way does your valve unit rotate?

Anyone know if the still out of stock Flair Plunger Key is fabricated out of plastic or metal?
LMWDP #151

upoverandbrew

#2: Post by upoverandbrew »

I suspect that it's was related to the portafilter turning, but admittedly I can't say I've thought too much about it -- it happens every once in awhile for me, I twist it back, and all's good. It's to me a small quirk that's an occasional bother, and even then only if I don't adjust it before starting up a shot; and even then, it takes a bit until it it has ever actually caused an issue with a shot.

I can't answer the plunger key question, but personally I've had no issue turning it by hand -- well, other than touching it when heated, which I don't recommend.
LMWDP #699

User avatar
Brewzologist
Supporter ♡

#3: Post by Brewzologist »

The plunger key is made of plastic.

MCal2003 (original poster)

#4: Post by MCal2003 (original poster) »

Hasn't been a real issue with the machine. Guessing maybe couple dozen pulls before it has rotated ~30 degrees.

Sent off an email to Flair today. Received a quick reply from Flair explaining the why?

"The plunger rotates since there is no linkage on the lever to make the drive of the piston linear, the whole system must tilt back and forth to accommodate the angle of force from the fixed lever pivot, and this tilt that the plunger goes through is a lot like a coin on a table. It doesn't just flop back and forth from edge to edge, it ends up rolling around the circumference."
LMWDP #151

jamesz

#5: Post by jamesz »

MCal2003 wrote:Wasn't sure until Flair added an accessory to deal with the problem that I had a one off issue. The rotating valve. Not sure what actually causes the assembly to slowly, but steady rotate. One thing I have notice is it is in a counter-clockwise direction. Same direction as securing the portafilter. Coincidence? Cause and effect?
my understanding: the rotation is caused by un-evenly distributed forces, including 1) friction forces on the plunger o-ring, and 2) the forces applied to the plunger through the stem.

With current design - plunger and stem are separate parts there is no way to stop plunger slow rotation unless the plunger and stem are joined together using a pin or similar design, like Strietman or JanYi.